Serena and Venus Williams’ abandoned and rotting childhood home, which has been in the family for 27 years, is hitting the auction block next month, a judge ruled.

The ruling comes after the sisters’ stepmom, Lakeisha Juanita Williams, allegedly forged the signature of her estranged spouse — Richard Williams — on the mortgage deeds of his four-bedroom, three-bathroom home in Palm Beach Gardens, Florida.

Lakeisha, 37, and who is 43 years younger than Richard, borrowed $255,000 from “hard lender” David Simon, which she then blew on a failed truck business, The Sun first reported.

Simon has spent the past five years attempting to get his money back, which now stands at roughly $584,000 with interest — and both Lakeisha and Richard, whose health is in decline, are responsible for the debt.

The home, which has since gone into foreclosure, will go up for auction with a starting bid of $1.42 million. Simon is expected to take the lion’s share from the proceeds.

It is the same home where Richard trained his tennis pro kids so that they could attend the Rick Macci Tennis Academy. It comes with two tennis courts.

Despite Lakeisha’s attempts to stall the auction, having twice filed for Chapter 13 bankruptcy, it was dismissed after she was unable to keep up with the repayment plan that would have saved the home.

Simon accused her of spending all her money on “fast food and frivolities” — and never paid a dollar on what she owed, court papers state.

A tax lien on the house from 2014 shows that Richard, 80, failed to pay almost $9,000 in property taxes.

The “Notice of Sale” states that it “will sell to the highest and best bidder for cash.”

Simon argued that, because of the home’s deteriorated state, it was uninsurable.

“Debtor is not providing adequate protection of Secured Creditor’s collateral, the House,” Simon says in the court filing. “The House is uninsured, the roof is leaking, and the collateral is in jeopardy of total loss.”

Richard, 80, purchased the property in 1995 for $355,000, according to property records.

Built in 1981, the waterfront estate stands on more than 10 acres of land.

Meanwhile, court documents from Richard’s own divorce battle included testimony from his doctor with claims that his health was in a dire state — and he is being looked after by his son in Atlanta.

The Post has reached out to reps for Serena and Venus for comment.